Method for preparing uniform granular magnesium hydrate by one-step reaction with ammonia bubbling method

Abstract

The invention relates to a method for preparing uniform granular magnesium hydrate by a one-step reaction with ammonia bubbling method. The method uses light fire powder (magnesia) as a raw material, uses ammonia sulfate, ammonium chloride or ammonium nitrate as an intermediate material and obtains ammonia gas and a magnesium salt solution by an ammonia distillation reaction; the ammonia gas and the magnesium salt solution contact in a bubbling reactor and generate a magnesium hydrate precipitation reaction under the action of an added surface active agent; product mother liquor is filtered after being aged for a suitable period of time, filtrate containing the ammonia sulfate, the ammonium chloride or the ammonium nitrate returns to an ammonia distillation system, and a filter cake is washed and dried to obtain a magnesium hydrate product in uniform granular shape and good dispersion state. The process prepares the magnesium hydrate by the one-step reaction with simple operation steps under mild reaction conditions, the product has uniform granular shape and can adjust and control the granular shape by changing the reaction conditions; and ammonium salt and ammonia gas circulate in the process. The invention has low production cost and little pollution, is suitable for mass production, and the product can be used as a raw material for producing high-purity magnesia or a flame-retardant additive of a polymer material.

Description

technical field [0001] The invention relates to a production method of a magnesium hydroxide product that can be used as a flame retardant, in particular to a method for preparing magnesium hydroxide with uniform particle shape by one-step reaction using an ammonia gas bubbling method. Background technique [0002] Magnesium Hydroxide (Mg(OH) 2 ) is a basic inorganic chemical product. The magnesium hydroxide prepared during the synthesis process is mostly used as a raw material for the production of high-purity magnesium oxide or a flame-retardant additive for polymer materials. In the application of these two aspects, in addition to the requirements on the purity, impurities and content of magnesium hydroxide products, there are usually special requirements on the particle shape, particle size and distribution, and crystal structure of the product. Magnesium oxide products can meet better use requirements. The properties of magnesium hydroxide products are related to the ...

AI Technical Summary

Problems solved by technology

There are some engineering technical problems in the batch process of ammonia water method: for example, in the production process of ammonia water method, with the continuous addition of ammonia water to the reaction system, water is brought in, and the NH in the reaction system 4 + , Mg 2+ The concentration is constantly changing and the whole system is uneven, which makes the formed magnesium hydroxide product particles poor in crystal form consistency, and the products are mostly mixtures of different crystal forms and particle shapes

The present invention aims at the deficiencies of the traditional process, and proposes a more reasonable process method, so as to solve the problems in the traditional process such as complex process, many operation steps, harsh production conditions and uneven product crystal forms.

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